Molds are efficient tools in order to give food products a specific form. Due to their essential role during the production process, i.e. they pass through a significant number of production stages, they are exposed to various mechanical, ambient (such as thermal) and chemical influences. For example, if the food products are removed by knocking the mold, the mold may have to withstand significant accelerations. When the mold is cleaned after production in a washing cycle, the mold is within an environment strongly influenced by chemicals that assist in cleaning the mold for the next production cycle. Here, the chemicals may have the potential to deteriorate the mold's material and therefore cause damage to the mold in the long run. In addition to mechanical and chemical loads, the ambient conditions surrounding the mold change significantly as well. After filling the mold, the mold may well be cooled down to temperatures below 0° C. in order to achieve a fast solidification of the food product. After the removal of the food product, the mold may be directly transferred to the washing process that normally requires temperatures of about 50° C. to 75° C. In other words, molds can be exposed to a substantial change in temperature during a short period of time.
Although many parameters may be used to optimize the production process, the extent to which they influence the state and integrity of the mold is not generally known. The hygienic requirements that have to be fulfilled according to the rules set out for the food industry narrows down the choice of materials during the design phase of such a mold to the materials certified for such a use. In other words, the best material and design to withstand the conditions the mold is exposed to during the production process may not be legitimate for use with food products.
Due to the repetitive use of molds during the production process, at some point problems such as fatigue may have negative effects on the production process. For example, a common failure is chipped-off pieces of the mold's material. This bears the risk that parts of the chipped-off material ends up within a food product. Therefore, in such cases, the production process is brought to an immediate halt. As a consequence, the food products that have been formed during the chipping-off have to be discarded, and the production line has to be checked for any residual pieces of material left within the machinery. Since it is hard to determine when the mold got damaged, a large number of food products may contain pieces of broken off material and the entire production run may have to be discarded to avert any risks to the health of the consumers. Only after such procedure, the production may continue. These safety measures result in a delay of the production and therefore in undesirable additional costs.
In order to avoid such costs, the molds are designed with high safety factors, leading to molds that are bigger in size and therefore heavier and harder to move. In addition, the lack of detailed knowledge concerning loads and the environmental influences acting on such a mold results in a rather empirical design principle. Hence, there is a need for optimization of the design of the mold and/or the production line and/or the production process to avoid the occurrence of failures of the mold during production such as chipped-off material due to fatigue and/or high loads.
Therefore, a first way to avoid structural problems with the molds is by optimizing their design. As laid out above, this option can not be fully exploited up to now due to the lack of knowledge about the loads acting on such a mold during production since sensors utilized for food production only register the state of the food product in the mold such as the temperature or the viscosity.
A second way is to develop means to detect a failure of the mold's material. For example, the German patent application DE 10 2004 012 580 A1 uses a camera and image recognition to determine if all food products were removed from a mold. Although this technology may be applied to monitor the integrity of the molds, such a technique is in general stationary and therefore limited to only one stage of the production.
Thus, DE 10 2004 012 580 could for example be used for the process and assembly for producing a confectionery product disclosed in EP 1 676 485 A1, which forms the basis for the two-part form of independent claim 1. EP 1 676 485 A1 describes an injection-molding device for molding a confectionery product which is shaped on all sides. It can be produced by (i) preparing an aerated sugar mass, (ii) injecting said mass in a mould cavity defined by two separable mold surfaces having a temperature below O° C., and (iii) separating the mold surfaces and removing the product.